A wide variety of fluorescent dyes, proteins and nanoparticles can be used for in vivo molecular imaging. Various targeting approaches to tag cells for in vivo imagining have been developed using reactive substrates for specific metabolic activities, antibody strategies to detect cell specific surface molecules and various transgenic strategies to introduce reporter proteins that make use of fluorescent and bioluminescent substrates. All of these approaches have led to an immense increase in the ability to track the activities of specific cells during differentiation or over the time course of specific biological processes such as metastasis or stem cell transplantation. This shared instrumentation proposal is for the purchase an IVIS Imagining System Spectrum Instrument (Xenogen/Caliper Life Sciences Inc). This new generation instrumentation is designed for high sensitivity imaging of bioluminescent and fluorescent probes in live small animals. The instrument has flexible imaging configurations for fluorescence, including reflection and transmission illumination options and large scannable filter sets. Multiple transillumination positions, combined with structured light for obtaining surface topography, provides the necessary data to perform 3D tomographic reconstructions. It will be used by 15 investigators funded by 6 R01 grants, 3 P01 grants, a K award, and 2 R21 NIH grants. Currently, all of the investigators are using retrieved tissues and cells after animal sacrifice to assess biological activities within these tissues, or have carried out collaborative studies at other facilities to obtain preliminary data using the proposed methodological approaches that would be supported by the new instrumentation. The use of the proposed instrumentation will enable us to follow in a high throughput, non- invasive and non destructive manner the activities of the tagged cells both in living animals and within intact post retrieval tissues. The availability of this instrumentation at Boston University Medical School adds an important new dimension to our technical abilities to take full advantage of many of the transgenic animals, cancer cell lines, and stem cell research projects that are ongoing at Boston University Medical School. The proposed instrumentation will be developed as a shared instrument core at both Boston University Medical School and will enable the numerous investigators to integrate this new imagining technology with other imaging and quantitative approaches such as cell sorting, confocal microscopy and microCT and MRI analysis that are all currently available as core facilities at Boston University. The research projects that will use this instrument address research projects in cancer, hematological, immunological, pulmonary, orthopedics, ophthalmology and renal research. The ability to follow cell activities, track cell growth and follow cell movement within living animals has immense relevance to development of stem cell, cancer and pharmacological therapies. Studies using this type of approach are also cost effective in terms of animal use allowing for many consecutive measurements of cell activities to be made with out euthanasia of the animal. [unreadable] [unreadable] [unreadable]